Changes in the spatiotemporal distribution of the timing and duration of the soil freeze–thaw status from 1979 to 2018 over the Tibetan Plateau

• DOI: 10.1002/joc.8617
• Publication Date: 2024-09-07T09:49:46Z
• Authors: Xin Lai; Siyuan Yao; Sixian Cen; Ge Zhang; Zhehao Zhang; Suyu Zhang

Abstract Changes in the soil freeze–thaw status will inevitably affect thermal conditions and properties of Tibetan Plateau (TP), thereby affecting its upper atmosphere, further afield East Asia even globally. In this study, using temperature simulated by Community Land Model Version 5.0 (CLM5.0), timing duration were divided into freeze start‐date, end‐date duration. Then, linear trend estimation, correlation analysis other methods, changes spatiotemporal distribution from 1979 to 2018 over TP analysed, relationships between them surface temperature, altitude latitude analysed. The results obtained as follows: (1) CLM5.0 can reasonably reproduce seasonal multilayer correlated well with observations. Simulated time also (2) spatial is characterized a delayed freezing, advanced thawing shortened northwest southeast TP. From 2018, start‐date postponed 7.3 days became at rate 1.9 per decade, while 6.4 1.7 13.7 3.6 decade. vary across different regions all areas has been past 39 years. Except for subcold zone arid TP, occurred earlier shortened, most significant humid regions, decade 6.3 (3) are significantly air elevation latitude, exceeding 99% confidence level. strongest, followed altitude, weaker. western stronger than that eastern change increases 3000 m above sea level, decreases m. greatest 29°N, delay minimal 33°N rates advancement shortening 35°N.